Project Summary ? Core B The three projects of this Program Project rely heavily on the use of mouse models to demonstrate their hypotheses. The purpose of the Morphology and Histology Core is therefore to consolidate equipment and expertise to provide the Investigators of these projects with state-of-the-art, quality controlled histologic and histomorphometric analyses of bone, pancreas and brain specimen as well as microCT and biomechanical analyses of mouse bones. The Core contribution to this Program Project will be at 5 levels: 1. Processing mouse specimens for histology and histomorphometry. Fixed and partially dehydrated mouse skeletons or pancreata will be provided to the Core by project investigators. These samples will then be embedded in plastic medium (vertebrae and long bones) or paraffin (pancreas). Fixed mouse brain specimen will be provided to the Core and either be sectioned without embedding or cryo-embedded and cryo-sectioned. 2. Performing specific stainings and immunostainings of mouse tissues sections. Classic histology stainings such as Hematoxylin/Eosin, Toluidine Blue, von Kossa/Van Gieson, Goldner trichrome, Cresyl violet as well as more specific reactive ones such as TUNEL and TRAP stainings will be performed by the Core personnel at the request of investigators. The Core will also perform immunohistochemistry studies using fluorescent and enzymatic detection. 3. Performing histomorphometric analyses of mouse bone, pancreas and brain specimens. The OsteoMeasure Histomorphometry System (OsteoMetrics Inc., Decatur, GA) will be used to assess static parameters, such as bone volume, trabecular number and cell counts, and dynamic parameters of bone formation, such as mineral apposition rates, from non-decalcified bone sections. It will also be used to quantify ?-cell mass in pancreas and TUNEL or BrdU positive cells in brain sections. Image J will be used for all other quantifications. The Core will provide investigators with histomorphometric data and will help them in evaluating their biological relevance. 4. Analyzing live mice and mouse bone specimen by microCT. Anesthesized mice or fixed and partially dehydrated mouse long bones and vertebrae will be provided to the Core by project investigators. These specimens will then be scanned using a VivaCT 40 microCT (Scanco Medical, Switzerland). 5. Performing biomechanical tests on mouse bone specimen. Flash frozen mouse long bones and vertebrae will be provided to the Core by project investigators. These samples will then be subjected to compression and 3-point bending tests.